TPS77701 Datasheet, PDF (18/21 Pages) Texas Instruments – FAST-TRANSIENT-RESPONSE 750-mA LOW-DROPOUT VOLTAGE REGULATORS

TPS77701, TPS77715, TPS77718, TPS77725, TPS77733 WITH RESET OUTPUT
TPS77801, TPS77815, TPS77818, TPS77825, TPS77833 WITH PG OUTPUT
FAST-TRANSIENT-RESPONSE 750-mA LOW-DROPOUT VOLTAGE REGULATORS
SLVS230A – SEPTEMBER 1999 – REVISED SEPTEMBER 1999
APPLICATION INFORMATION
power dissipation and junction temperature
Specified regulator operation is assured to a junction temperature of 125°C; the maximum junction temperature
should be restricted to 125°C under normal operating conditions. This restriction limits the power dissipation
the regulator can handle in any given application. To ensure the junction temperature is within acceptable limits,
calculate the maximum allowable dissipation, P_D(max), and the actual dissipation, P_D, which must be less than
or equal to P_D(max).
The maximum-power-dissipation limit is determined using the following equation:
+ ^* PD(max)
TJmax TA
R _qJA
Where
T_Jmax is the maximum allowable junction temperature
R_θJA is the thermal resistance junction-to-ambient for the package, i.e., 176°C/W for the 8-terminal
SOIC and 32.6°C/W for the 20-terminal PWP with no airflow.
T_A is the ambient temperature.
+ ǒ * Ǔ The regulator dissipation is calculated using:
PD VI VO IO
Power dissipation resulting from quiescent current is negligible. Excessive power dissipation will trigger the
thermal protection circuit.
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